This logo can be any color, you should choose a color that suits the nature of the business, which means if you own a business with a young character, dynamic, or perhaps high-tech, you can combine design happy colors more like lime green, orange, light blue, etc.. If you have a solid and serious business use quieter colors like burgundy, black, deep blue. Combination of gray and silver color logo, take the design to more innovative but not garish.